Telegraph transmitter



Aug. 18, 1942. L. M.- POT-rs TELEGRAPH TRANSMITTER Filed Feb, l5, 1940 2 SheetsSheet l INVENTOR. LOUIS M. POTTS A ORNEY.

TELEGRAPH TRANSMITTER `Fled Feb. 15, 1940 2 .Sheets-Sheet 2 FIG.2

INVEN LOUIS M. P S

BY I

` TTORNEY.

Patented Aug. 18, 1942 UNITED *STATES ,e PA'IflEIN'I", *OFFICE TELEGRAPH TRANSMITTER- Louis M.Potts,`.Evanston, Ill., assignor to Tele- 1 type Corporation, of Delaware Chicago, Ill., Va corporation Application February 15, 1940, Serial No. 319,025

`ranged tape .advancing perforationsf and with transversely arranged permutative distributions of code perforations.` In the preparation of transmission tape conventionally, y a keyboard is employed to control the `operation l ofpunches which respond to the depression of l character key levers to-perforate code perforations .in the tape correspondingly.. l.

As the code perforated tape -is issued from the preparing machine it is customarily threaded into a tape transmitting apparatus Which,in-re'sponse to the arrangement of perforationsin each transverse code alignment, causes to-beelectrically conditioned avset of distributor segments or contacts. The latter aretraversed sequentially and through their control are generated permutation code line signals correspondingimpulse for impulse to the'distribution of perforations in the tape. It is herewith proposed to combine the aforesaid tapel preparing or perforatingmechanism withsaldtape controlled transmitting apparatus withinfa single unit for the purpose of utilizing thefprepared tape for transmission as soon after its preparation as is practical, with minimum slack tape accumulation intervening the point lof Vtape preparationy and the point of signal transmission.

While combined apparatus vfor perforating `a tape and for transmitting-signalsover a line under the control of the perforated tape has been known before it is-novv proposed in accordance with the present invention tov enable the trans'- mission of line signals so asA to utilize promptly all of the prepared tape up to and including the very last transverse row of 4perforations notwithstanding the distance which intervenes the perforating punches andthe tape transmitting feelers and yet Without incurring loss of line time.

Accordingly, the main object of the present invention resides-inthe provision of a combined tape perforating apparatus 4.with an automatic transmitter:which may. be automatically started upon the accumulation Aof a perforated tape surplus, and automatically arrested upon vthe exhaustionfoff a perforatedtapesurplus and the transmission of the group of signals forthe last transverse row of code perforations in .thetapa Another object. oi the present invention is the provision 'of apparatus-for back stepping perforated tape through both preparing and. sensing apparatus simultaneously and for disabling the transmitting apparatus commensuratelylto prevent duplicate transmission of those signalsthus back stepped.

A feature of the invention resides in the provision of mechanism which will permit a full and complete transmission oi message material including that which intervenes the two essential components of the apparatus without incurring wasteincident to the feeding of blank tape in order to advance the nalor concluding signals of a message to the tape transmission feelers.

In its essential embodiment, the present invention features a unitary supporting structure having two principal apparatus components. One is a keyboard perforator inwhich a conventional keyboard mechanism conditions a set of punches which are then operated by a power source to make code combination and feed hole perforations in a tape. A second component is a tape transmitter with its sensing apparatus arranged so as to align with the perforating punches for the purpose of maintaining continuous co-operation with the tape asit emerges from the perforating component. Between the two components is a space wherein prepared tape may be permitted to accumulate so long as the-keyboard perforator is operating at a greater rate than is the transmitter unit. As the surplus accumulation of tape between the two components is eX- hausted, a lever, especially responsive to this condition, acts to arrest further operation of the transmitter as well as the transmitter tape feed apparatus.

In order to permit that portion of the tape which intervenes the two components to be advanced through the transmitter, as when no further message matter is'being prepared by the keyboard, a special key lever is provided which establishes conditions to feed out a predetermined amount of tape from the perforator, permitting thereby feeding out of more of the tape and of the restarting of the transmitter which there-V upon continues in operation until the additional tape is exhausted. Subsequently, and for the purpose of retracting that portion of the tape which has been fed out in response tothe operation of the aforesaid special key lever, a tape n retracting apparatus may be set into operationv response to a-further special key lever restoring the condition of the tape which prevailed before the first mentioned special key lever was operated while also disabling the signal transmitting apparatus to a limited extent commensurate with the retracted portion of the message so that upon starting transmission of a succeeding message, the tail end of the preceding message will not again be transmitted.

By means of a circuit switching arrangement utilized in conjunction with the present system, transmission tape may be prepared locally, and immediately tested at the local station through the use of a monitoring printer which may also serve as a home recorder. Under the control of a ground switch, transmission may be directed to a remote station after test or, if desired, instantly upon the preparation of the tape. In the event of any errors discovered in the tape, mechanism is herewith provided for retracting portions of the tape through the use of power driven apparatus for feeding out unperforated sections of tape, and for resuming tape transmission following a retraction operation together with a limited safeguard against the retransmission of retracted signals, thereby avoiding undesirable Iduplication and waste.

For a more comprehensive understanding of the present invention, reference will now be had to the more detailed description following hereinafter and to the accompanying drawings in which like reference characters designate corresponding parts throughout and, in which Fig. 1 is a transverse sectional View through a combined keyboard perforating and tape transmitting apparatus fashioned in accordance with the principles of the present invention;

Fig. 2 is a schematic circuit illustration of a transmission system having a preferred embodiment of the present invention applied thereto;

Fig. 3 is a diagrammatic outline of a gear train and power distribution system such as may be employed for the purpose of operating the preferred structure illustrated in Fig. 1, and

Fig. 4 is a detailed sectional view of a modified embodiment of the apparatus driving train and auxiliary mechanism.

The reference character II denotes a keyboard hase casting in which are pivotally supported an alignment of key levers I2, the keytops of which are in the foreportion which is omitted from view in Fig. l. The depression of any key lever I2 causes an individual placement of a set of ve pairs of coded bars I3 each pair articulated with a corresponding longitudinally movable bar I4 through the intermediate agency of a T-lever I5 in a manner now well known in the keyboard telegraph art. There being five longitudinally shiftable bars I4 as well as a common release bar generally similar to one of the bars I4, it is to be accepted that the five bars I4 may be moved towards the right or left in accordance with each individual code combination but that the common release bar which is connected to the trip rod I6 is invariably shifted towards the left for each keyboard operation.

The five bars I4 are connected through individual links I1 with ve vertically supported pivot levers I3 causing their motion to be translated into 'a longitudinal shifting of a corresponding set of five interponents I9, to which the vertical levers I8 are connected through the intermediate agency of connecting links ZI. As the several interponents I9 are placed for each operation of a key lever I2, their leftward extremities may be made to align with or to avoid the lowermost extremities of a set of five punches 22 at the same time that invariably shifted trip I 6 is moved leftwardly to engage the lowermost extremity 23 of a release pawl 24.

In addition to the five punches 22 which are arranged in transverse alignment and which are operable permutably to make the code perforations in a tape 25, a single punch element 26 is provided a short distance to the right of and therefore in advance of the punches 22 which single punch is invariably operated to perforate feed holes in the tape because its interponent 21 is presented at all times beneath the punch extremity 26 so as to be operated together with any of the punches 22 whose interponents are engaged by the common perforating hammer 28 pivoted at 29 whose lugs 3I and 32 strike against the interponent extremities just beneath the punches 22 and 26, respectively.

As has been sai-d, the operation of any key lever I2 not only causes the permutative placement of the several interponents I9 but also through trip I6 causes the withdrawal of stop pawl 24 from clutch disc shoulder 33. Shaft 34 is thereupon permitted to rotate clockwise, it being frictionally associated (not shown) with a driven gear 35 which meshes with a driver 36, Fig. 3. Shaft 34 carries two operating cams indicated 31 and 38, the former for actuating one arm 33 of a bell crank whose other arm is pivotally articulated at 4I to the tape advancing pawl 42 as well as to the counting pawl 43 which depends from the same pivot 4I. Attention is directed to pawl 42 which is illustrated in its rest position in Fig. 1. Under this circumstance, its tooth is clear of the ratchet wheel 48 so that the latter could be rotated without any interference to or by the pawl 42, but yet upon moving said pawl 42 downwardly its tooth is adapted to enter into engagement with an awaiting ratchet wheel tooth and to thereby effect a one tooth-step motion to the wheel 48 and its associated elements for a purpose to be discussed. Upon its return movement the pawl 42 slips over the intervening tooth because of its sloping or cammng surface engagement therewith, whereas the shaft 49 is prevented from following by the action of any well known tensioning or detenting element (not illustrated). The other cam 38 actuates with its brief-interval apex one arm 44 of a power bell crank whose other arm 45 overlies the punch operating hammer 28 so that upon its actuation counterclockwise about pivot 46, hammer 28 will be struck and rocked clockwise, thrusting its abutments 3| and 32 upwardly and against interponents I9 and 21, respectively. The apices of both cams 31 and 38 are located so as to perform their respective functions towards the end of the rotary cycle of shaft 34 with cam 38 causing the punching operation to be executed in advance of theV time that cam 31 depresses pawl 42 and causes the advance of the tape 25 for the presentation of a succeeding surface area in punching position.

Pawl 42 is urged clockwise about its pivot 4I by a spring 41 and is normally maintained yby a. stop pin 49 with its tooth out of engagement with its ratchet wheel 48, a suitable detent apparatus (not shown) being contemplated for holding the shaft 49 in set position. Shaft 49 carries not yonly the lpawl ratchet wheel 48 but also a conventional tape feed sprocket 5I Whose teeth are adapted to align with the tape feed perforations made by punch 26.

From the foregoing explanation it follows that as a result ofdepression of a character key lever l2, shaft 34 is permitted to rotate throughout one revolution,and its cams -31 yand 38 `Wil1,dur ing this time, cause to be actuated certain' ones of the code perforating punches 22 depending upon the character of the signal which relates to the particularly actuated key lever I2,` but punch 26, because its interponent 21 is ever in the effective position, at all `times causes tobe made the tape advancing perforation utilized by i the teeth lof sprocket Moreover, as a result y of the actuation of bell crank 39, pawl 42 causes the tape to `advan-ce to -a succeeding recording area, but 'pawl 43 which also pivots at 4| may `engage a counting segment 52 under certain conditions of operation only, to be discussed later. At this time said pawl 43 is withheld by theengaging pin 54 of retractile lever 53.`

As tape 25 issues from the punch block 55 it tends to accumulate in a lloop formation as' indicated (dotted outline) in Fig; 1. When the proportions of this tape accumulation are greater than that'of a minimum loop, such as is just suflicient to urge against the extremity 56 of Ibell ycrank 51, the latter member is permitted to respond to the urge of its spring58 and rotate counterclockwise about 'shaft 59 whereat it is conveniently pivoted. Because spring 58 is more powerful than is spring '6| of clutch stop bell crank 62, the latter member is rotated clockwise about pivot 63 causing to be Withdrawn its interfering arm 64 from the tooth 65 of a friction clutch disc carried by a frictionalli7 driven sleeve assembly which surroundsand is propelled by constantly rotating transmitter shaft 66 freeing said sleeve for rotation.

`Sin-ce gear 61 (Fig. 3) of shaft 66 is' driven by driving gear 36, it, too, tends to rotate in a clockwise direction, as viewed in Fig 1, imparting a similar movement to the driven shaft 66 'who-se driven sleeve carries a pair of 'cam elements designated bytheir apices 68 and 69. Apex 69 is one which, during the rest position of thev sleeve assembly, engages the vertical arm of a bell crank lever 1| pivoted at 12 and normally urged counterclockwise by spring 10, whose horizontal arm carries integrally `therewith 'a transversely extending retraction bar 13. Bar 13 overlies a set of ve feeler levers 14 which members 'are also pivoted at 12 and are urged by individual springs 15 in a counterclockwise direction so as to endeavor to present their several feeler pins 16 against the surface of theperforated tape 25, those pins 16 which encounter perforations in their corresponding positions being permitted to rotate to a further extent in a counterclockwise direction than the remaining ones of said levers 14 which do not so encounter perforations. The extent to which levers 14 arepermitted to rotate by the presence or absence of 'perforations in the tape manifests itself by the corresponding disposition of a set of individual contacts 11, Fig. 2, that is to sa'y, the more fully rotated feeler levers mature retains the distributor la-rml83 lies `inv'a supervisory f circuit which includes in' series the contact pairs 85 and 86 which are vshown also in Fig. land which' are under the mechanical su- -pervision of bell crank lever 1| and multi-arm lever |23 so that magnet 82 may 'be energized only when bell crank 1| is in its counterclockwise extremity with retraction bar 13 having released the several feeler levers 14 and lever |23ifis nor-` mal. f'

"Assembly" sleeve of shaft 66 when released for rotation by thev withdrawal of -bell crank arm 64 from its 'stop disc 65 may continue 'to rotate lso-long as lthe tape 'slack probing arm 56`is per# mittedto rise aboveA the taut-tape level which condition `has already beenv defined above.v As each rotary cycle is started from the position indicated in Fig. 1, apex 69 rides off the extremity of belly crank 1| closing the contact pair 85 and permitting the several feeler levers 14 to rise as already discussed. As a result of the closure of Contact pair 85, contact 86 being normally closed,. the energizingV circuit for magnet 82 is completed causing its armaturefto be Withdrawn `and starting the distributor arm 83 into rotation. In Fig. 2 this arm vhas been indicated as driven from shaft 66, it being understood that a separate friction clutch be provided therefor .or, if preferred, another shaft having the same rate of speed as has shaft 66 may beprovided therefor. i

Toward the end of the cycleof revolution of cams 69 and 68, the transmitting distributor brush arm 83, Fig. 2, having'had time to traverse all of the transmittingsegments 18, cam apex 68 encounters and rocks the follower arm 81 ofa bell crank lever whose opposite arm 88 carries the pawl pivot 89 causing said bell crank lever to be rotated clockwise about the pivotV 12. This operation lowers the tape advancing pawl 9| which thereupon, engaging one of the teeth in the ratchet wheel 92, rotates the transmitter tape feed shaft 59 one tooth-step distance in a Vcounterclockwise direction as viewed in Fig. 1. Here, too,A it will be noted as in theicase of perforator shaft 49 the normal position of feed pawl 9| is raised and is clear of thev teeth of said ratchet 92 for a purpose which Willbe indicated later. When the cam apex 68 passes beyond the follower .arm extremity it permits the bell crank 61.-88 to return counterclockwise to its normal 14 responding to perforations in the tape effect the closure of said contact pairs11 Iwhile those Whose pins 16 encounter no perforations fail to effect the closure of their individual Contact pairs.

Effectively, contact lpairs 11 ,each operate to present or withhold battery from an associated one of a set of distributor segments 18 of a conventional start-stop rotary transmitting distributor whose collector ring 19 is connected to loutgoing line 6|. In observing Fig. 2 one may note that the -.distributor start magnet 82 whose ar.

influence on bell crank arrestor 62-64 permits the Ylatter member to again present its interfering extremity 64in the path of clutch disc 65. However,`in the event of a taut-tape condition shaft 66 cam assembly will be arrested in the manner described and further transmission will be prevented because in its arrested condition apex 69, holding bell crank arm 1| in the indicated position maintains the energizing circuit for start magnet 82 broken.

The space which intervenes the keyboard perforating mechanism and the tape sensers 14 is such that an intervening strip of tape 25 which is sufficiently taut to arrest further transmission will preferably contain, in the instant embodiment, six code signals. Upon the resumption of operation of the keyboard mechanism additional slack will be introduced, the transmitter started, and these signals will issue in the customary manner already described. However, in the event that the keyboard operator has completed the perforation of a message and has no further signalling to do and therefore no perforations made in the tape 25, means are provided whereby under but a single supervisory key manipulation the last six signals which are found in the intervening strip portion of the tape may be advanced for the purpose of completing the message transmission.

M essaye end run-o1? To transmit the final six signals as discussed above the operator depresses a key lever and as a result the multiple armed lever |02 is rotated clockwise against the tendency of its return spring until its remote extremity |03 passing over the tooth of latch pawl |04 is held thereat. In consequence of this the sidewardly extending lip of its arm |05 retracts the clutch release pawl 24 permitting shaft 34 to enter upon several continuous cycles of rotation. As a result of the movement of arm |06 of lever |02 bell crank lever |01 together with its retraction bail |08 is rotated clockwise against the tendency of a spring |09 which effects the rocking of all of the supporting levers to the right, thereby withdrawing the interponents |9 so that none of them underlies its code perforating punch 22. Incidentally, the holding of all interponents I9 in their right-hand position under the action of bell crank lever IUT-|08 serves also to lock the keyboard against operation.

As a further result of the movement of arm |35 projection |!2 thereof is moved clockwise and latch 53 is released to the influence of its spring ||3. In consequence thereof, dependent pawl 43 is freed and permitted to engage the teeth of counting segment 52. A tooth ||4 integral with latch 53 acts meanwhile as a detent to resist the restorative influence of involute return spring l of segment 52 as the latter proceeds to toll six operation cycles.

There follows six complete revolutions of shaft 34 during which the effect of its cam 38 on bell crank lever 44-45 is idle because all of the interponents I9 are withdrawn from effective position. The special interponent 2l which acts upon punch 26 in making the tape feed perforations, however, continues in effect as before. Under these circumstances of operation, cam 3l acting on the follower arm 39 not only operates the tape feed pawl 42 as described in connection with the ordinary keyboard operation, but also at this time dependent pawl 43 rotates ratchet segment 52 one tooth step at a time until the bottom surface thereof engages the waiting arm of bell crank latch |04. This encounter releases said latch |04 thereby freeing the multi-arm lever |02 whose spring thereupon returns the several dependent elements to the normal position as indicated in Fig. l.

Meanwhile shaft 34 has been permitted to rotate throughout six cycles a's determined by the distance between the contacting surface of ratchet segment 52 and its instant of effective operation upon release latch |54. Accordingly, tape feed pawl 42 has been permitted to advance the tape 25 and to form a slack loop in the accumulation space which intervenes the two principal apparatuses thereby permitting the probing arm 53 of bell crank lever 56-51 to rotate in a counterclockwise direction and initiate transmission as before. The transmitter apparatus will then resume transmission for six additional cycles of rotation (commensurate with the then available surplus of signals) whereupon the tape 25 will again become taut and arrest transmission by reason of its effect upon probing arm 56. The intervening strip of tape 25 now found between the two apparatuses will contain no transmission signals but instead six blank (unperforated except for the feed holes) signal areas. Under the circumstances, if tape preparation were to be resumed six blank line signals would necessarily intervene between the preceding message and the succeeding one.

In order to forestall this possible waste of line time and for the further reason that a succession of blank signals might, as in the case of certain receiving station apparatus, initiate special responses predeterminately intended to be operated in the event of a succession of purposefully prepared blank signals (such as remote motor control, send-receive break control, etc.), which responses would not be intended at a message starting period, means are provided for retracting the unperforated intervening area into the tape perforator, and restoring the final six perforated signals of the preceding message to the intervening area so as to permit the installation of succeeding message signals to occupy the otherwise blank positions.

Tape-out back feed To backfeed the tape six signal positions, an operator depresses the key lever indicated |2| (at the left of Fig. 1) as a result of which there are rotated counterclockwise two multiple arm levers |22 and |23. In consequence of the movement of lever |23, its remote extremity |24 overrides the latching tooth of a pawl |25, symmetrical and opposite to latch |84 causing said lever |23 to be latched in its counterclockwise position pending subsequent release. Further, as a result of the withdrawal of one of its arms |26, bell crank 96 is permitted to respond to the urge of its spring, rotating clockwise about its pivot 3l and shifting its restraining pin 95 out of holding position with respect to dependent pawl 93. Also, a detent tooth |21 integral with bell crank 96 is permitted along with dependent pawl 94 to engage the teeth of a counting ratchet segment 94 already described. As a result of the movement of arm |28 of lever |23, restraining pin |29 engaging the dependent arms i of the several feeler levers 14, is caused to move the latter members clockwise withdrawing the several feeler pins 'i6 for the effective interval of operation of the instant back feeding apparatus.

As a result of the counterclockwise rotation of multiple arm lever |22, the influence of its spring |32 is overcome and the arresting tooth of arm |33 is moved out of the path of a particular one of the six equidistant stop pins |34, in escape wheel and gear |35, see also Fig. 3. This permits shaft 65, which is frictionally coupled thereto, to rotate gear |35 to a limited extent, but another arm |36 of lever 22, being interposed in the path of an oncoming pin |34, will prevent the rotation of gear wheel |35 beyond a distance somewhat less than degrees,V awaiting the release of manually operable lever |2|. After this, the arresting tooth of arm |33 will again become effective at precisely 120 degrees. Arms |33 and |36 actinaicomplementary fashion in the manner of an `escapement pallet, wheel |35,pby,virtue of its pins |34, being the counterpart of a conventional pallet wheel.

At this time, attention will be given to the distribution of power which, in accordance with the preferred contemplation, originates with driving gear 36, Fig. `3. As has already been said, through gear `35 and a clutch mechanism represented by release disc 33, power is communicated to the cam, assembly carried Aby shaft 34. ,Throughgear 61, which isV also in mesh with driving gear 36, power is communicated to shaft 66, and by, means ofthe clutches represented by stop element` 65, and a` secondary clutch` controlled by theiescape arms |33 and |36, power iscommunicated to the driving gear |35. Gear |35 in `turn drives intermediate idler. gears` |31 and |40 in train, and of these the latter gear meshes with a driven gear |38 carried i by a stub shaft |39` appropriately mountedin a stationary portion of the supporting structure.- On the same shaft |39, and integrally associated with driven gear |38is a driving `gear 4| which consists of 4six component driving .segments |42 with intervening mutilated or` toothless sections, the gear segments |42 of said driving gear |4| being adapted to mesh simultaneouslywith drivenpinions |43 and |44 secured to shafts 59 and 49, respectively, of said l transmitting yand perforating units. Thus, when gear,V |35 is permitted to describe one-sixth of a revolution in .a Iclockwise. direction under the control of 'escape pins |34 and pallet arms |33. and |36, as already stated, a measured degree,of rotation in the opposite direction is imparted to the drivinggear |4| through the intermediate agency `of idlers |31 and |46 and gear wheel |38, and in so doing, associated segments 42 of s aid wheel |4| are brought .into meshingengagernentwith driven pinions |43 and |44 and causingvshafts 53 and 49, respectively, to be rotated clockwise simultaneously a distancecor responding `to six perforated signals. This4 will cause the tape `to be fed backward in both the record reader `as Well as on the perforator.

In connection with mutilated gear wheel it may be observed that each group of teeth |42 has been farbitrarilyindicated as comprising, a certain number of teeth. It is to be understood that this number of teeth may Vary in accordance with the proportioning thereofwith respect` to the peripheral surface` which contacts the tape, that is to say, where smaller teeth are preferred a larger number ofnthem may correspond to the distance o-f movement required to backfeed the tape six code perforations, and where larger teeth 4arepreferred a fewer number of them will so correspond., In each case, the number of tteeth! in each group |42 for a given conditionwill bethe same, so that during repeated operations `of wheel |4| the same relationship of shafts 49 and 59 will be maintained. Meanwhile,- however, and for the reason that the intervening tape portion is maintained taut, transmission is prevented on account of the effective condition of bell crank stop lever 62-64 whichis holding apex-.69 in place-to permit contact pair 85 to spring ajar. Accordingly, distributor magnet |32 will remain de-ener'gized,

causing tobe. restrained the distributor brush armf83.` Followingthe actuation ofbackstep control lever |2|,-.the tape `25A isv fed backwardly to-an extent commensurate with sixfcode signals,-

for the purpose of presenting the unperforated areas before the punches 22. Thereafter six code perforations are made in the tape to fill in the blank areas and prevent waste, shaft 66 is released pursuant to the control effected by bell crank member 56-51, butA no signals will be transmitted for the six codes relating to the previous message, because the transmitting distributor release relay 82 cannot yet be energized due to the open circuit condition at `contact 86. As a result of the operation of cam apex 68, however, tape feed lever 88 will be reciprocated together with tape step pawl 9| and its associated dependent pawl 93, with the effect of advancing the tape 25 in the usual manner and with the effect of stepping the counting segment 94 until its lowermost portion collides with and actuates release latch |25.

Thereupon, lever |23 will be restored in response to its spring and the tape feelers 14 will be permitted to resume their normal manner of operation, that is, of variously impressing current on the transmitting segments 18. It will be understood then that following the advancement of the six code perforations, relating to a preceding message or group of signals, beyond the sensing unit (feelers 14), subsequent perforations will cause the tape feelers 14 to actuate their contact pairs 11 while contact pair 85 will also be closed to effect transmission by thc distributor in the conventional manner.

If it should be desired to backstep the tape to an extent more than six code perforations, as just described, this may be done in multiples of six code signal steps by repeated depression of the backstep lever |2|,

Operation of backstep key lever |2| in excess of the first operation in a sequence, as just described, causes multiple arm lever |22 to be operated repeatedly, but not so with lever |23, which is maintained latched by the action of latching bell crank |25. The effect of operating lever |2| repeatedly causes arm |33 to be withdrawn from the particular escapement pin |34 against which it had been resting, and presenting its arm |36 into the path .of the oncoming pin |34. As the operators nger is withdrawn from key lever |2|, springl |32 restores multiple arm lever |22 to its normal position whereat arm |33 is again interposed into the path of the pin |34 which had been held by arm |36, as the latter is withdrawn to its clearance position as indicated in Fig. 1.

Repeated backstepping operations, in accordance with the particular disclosure, will not prevent resumption of signal transmission save for the rst six signals. Thereafter, lever |23 being released by latching bell crank |25, in a manner as already described, signal transmission will resume unless manually prevented as by manually withholding the feeler levers 14, or by otherwise introducing spacing signal conditions to the distributor segments 18. It isto be understood, therefore, that while,.in accordance with the instant embodiment, repeat transmission of signals in the casemof retractedtape operation is prevented only for a limited number of signal conditions,.the indicated principle of operation may, if desired, be structurally enlarged so as to embrace eifectively a larger quantity of retracted signal conditions. Likewise, in the operation of signal retracting apparatus, the indicated prinfciples of construction may be so enlarged Ias to embrace any other number of signal .operations differing from that indicated arbitrarily above.

Modification of tape-out .back feed In Fig. 4 there is illustrated theessential arrangement of tape advancing shafts i9 and 59 not unlike that shown in the preferred embodiment, Fig. l, .but having in addition upon stub shaft |39, a locking cam for operating the locking bell crank lever lill-|08 during the interim of back feeding the tape 25. It will -be observed that as in the case of the preferred embodiment the mutilated gear wheel IM .being provided with groups of teeth |42 designed to enga-ge simultaneously the driven gear wheels |53 and |44 of shafts 59 and 49, respectively, for the purpose of rotating them clockwise to back feed the tape, causes said cam It! to interpose one of its six apices |52 against the follower tooth |63 of a lever |54 whose opposite end is bent at right angles indicated IE5 to engage the sidew-ardly extending arm of said blocking bell crank lever IUT-|03. As a result, this bell crank lever becomes effective in the same manner and for the same purpose as `discussed above in connection with the operation of multiple arm lever |02 in response to the manipulation of key |91. Thus, keying is prevented during the interim of back feeding operation for the obvious purpose of avoiding inadvertent tape perforating at a time when this operation is inconsistent with the immediate performance of the machine.

Calling attention Vnow to Fig. 2, there will be observed in outgoing line 8| a relay |68 which is symbolic of a home recorder and monitoring printer. This instrument may be of the same type yas that provided at the remote station and thereat indicated |69. Under conventional setup, as illustrated in this figure, the two printers are connected in series along with the transmittingV distributor of the home station and its corresponding device ITI at the remote station. By closing the manual switch |72, however, the outgoing circuit is grounded for the purpose of preventing transmission to the remote station, whereby the home printer |68 serves as a monitoring instrument to apprise an operator who may not be able to read directly from the perforated tape as to whether the perforations correspond with the intended text. In the event of error, the tape may be retracted, as above described, through the use of key lever |2I until the erroneous portion is in line with the perforation made, affording an opportunity in this manner of deleting portions of the text, which may be done by superimposing all marking signals (perforations in each position) which portions of the teXt are to be deleted. From this it will be seen that the conveniences of the instant apparatus in affording means for rapidly retracting the tape serves as an aid in obtaining eiiiciency as against the heretofore known methods of singlestep retraction.

While the present invention has been illustrated and described in contemplation of a specific embodiment as noted in the detailed foregoing description, and in the specic drawings accompanying herewith, it is to be understood, nevertheless, that certain changes and modications may be instituted without departing from the spirit or scope herein outlined. Accordingly, it is expressly reserved not to be limited by the specic language in the foregoing specification nor by the structure indicated in the accompanying drawings, except as limited by the hereinafter appended claims.

What is claimed ist p l. In a perforated-tape controlling mechanism, a tape feed device having means for meshing engagement with perforations in a signal bearing tape, means for actuating said device one signal-step distance coincident with each signal control operation of said mechanism, and means responsive to a single manual supervisory operation for advancing said tape through a predetermined number of signal positions.

2. In a tape perforating key lever apparatus, a sprocket wheel having teeth adapted to mesh with perforations in a control form, a pawl and ratchet actuating mechanism for stepping said wheel one tooth distance for each signal operation, a power source, and means responsive to a single manual key lever control actuation for coupling said power source to said sprocket wheel for moving said Wheel a plural tooth distance.

3. In a tape perforating apparatus, a tape advancing shaft comprising a sprocket wheel for engaging perforations in a tape, a ratchet wheel integral with said sprocket wheel, a pawl for engaging said ratchet wheel, a power source, cam mechanism driven by said source for actuating said ratchet wheel one tooth distance, and means for clutching said power source to said shaft directly for imparting rotary movement to said shaft for obtaining a plural tooth distance of operation.

4. In combination, a setl of perforating punches corresponding in number to the components of va permutation code, a perforating punch for making tape feed holes in advance of said set of permutation code punches, a tape feed sprocket and ratchet wheel integral therewith a pawl for actuating said ratchet wheel for single step tapeadvancing operations, a driven gear integrally,

associated withA said ratchet wheel and tape feed sprocket wheels, and means for coupling power to said driven gear for actuating said tape feed sprocket to perform a plurality of single step operations.

5. In a keyboard perforator, a set of key levers, a set of punches, a power driven shaft, means under the control of said key levers for conditioning said set of punches for operation by said power driven shaft, means for advancing a tape one step distance for each manipulation of one of said key levers, a special key lever, and means for advancing said tape a distance greater than one step in response to the operation of said special key lever.

6. In a combined keyboard perforator and taper ing means to drive them in a tape retracting direction.

7. In combination, a keyboard perforating apparatus and a tape transmitting apparatus, said keyboard perforating apparatus including a tape advancing shaft having thereon a tape engaging sprocket, a pawl actuated ratchet Wheel and a driven gear, said tape transmitting apparatus including a shaft having thereon a tape engag- `and key lever controlledrclutching mechanismfor engaging said power source to said driver to operate said tape transmitting and keyboard perforating apparatuses.

. 8. The combination set forth in claim 7 including means for suspending subsequent transmission by said tape transmitting apparatus for a limited interval upon the actuation of said clutching mechanism.

9. In `a tape transmitting apparatus, a transmitting distributor, a tape sensing and advancing` mechanism, a power source for imparting motion tosaid distributor and said mechanism, said power source including cam means forimparting step by step movement to a tape for moving` it in one direction andgear means for movement of said tape in an opposite direction to obtain. multiple step backspace operation.

10. In combination, a tape transmitting apparatus including, a transmitting distributor, a tape sensing mechanism, a tape advancing mechanism, a tape perforating apparatus comprising a keyboard, a set of tape punches, means under the control of said keyboard for preconditioning said punches permutably, means for advancing said tape following each keyboard operation, and a special keyboard control member responsive to a single manipulation impulse for disabling said punch preconditioning apparatus and for operating said .tape advancing mechanism a plurality of times.

11. A perforator-transmitter unit apparatus including, a keyboard comprising a plurality of manually operable key levers, a punch block associated with said keyboard including a set of permutation code punches, a tape feed hole punch, interponents for enabling the operation of said code punches under the control of said keyboard, a tape advancing sprocket, power shaft includingmeans for actuatingsaid sprocket for single step feed operation, ay tape sensing apparatus spaced from said tape punch block to permit of tape accumulation therebetween, means controlled by the tape accumulation between said punch block andsaid transmitter sensing mechanism for initiating the performance of 4said transmitter, and manual control means forV retracting said tape from both said sensing mechanisrnand said block.

` 12. In a combined perforator and transmitter unit, a step-by-step tape feed apparatus in the perforator portion of said unit, a step-by-step tape feed apparatus in the transmitting portion of said unit, and powerV driven tape moving apparatus for feeding the tape a distance corresponding toa plurality of steps at a time in a direction reverse to that of said tape feed apparatuses.

13. In combination, a permutation code perforating apparatus, a permutation code transmitting distributor, and a permutation code tape sensing apparatus, a rotary power` source for actuatingsaid tape perforating and sensing apparatuses and said distributor, means responsive to alpredetermined accumulation of perforatedA tape between. said. tape A.perforating and tape sensing, apparatuses for initiating theY operation of `said transmitting` distributor, and` means responsive .to a special operation `ofsaid tape sensing apparatus for preventingthe initiation of said transmitting distributor-by said tape perforating apparatus.

. 14. In combination, a control form preparing mechanism, a control form sensing mechanism, a control form feeding means associated with said preparing mechanism, a control form feeding means associated with said sensing mechanism, and common operating means to simultaneously operate both -said feeding means to retract the form` the same number of unit spaces.

15. In an apparatus for conveying control form, a sprocketwheel having teeth for engaging perforations in said form, a ratchet wheel integrally associated with said sprocket wheel, a driven gear integrally `associated with said sprocket wheel, a power shaft, cam means operable by said power shaft for reciprocating a ratchet wheel actuatorto advance said form in one direction step-by-step, a gear train for rotating said sprocket wheel in a direction opposite to that of said step-by-step actuating means, a single revolution clutch means for imparting motion to said cam actuator, and means for maintaining the driving relation of said gear train and said power shaft for extended intervals of time.

1 6. In a keyboard perforating apparatus, a set of principal key levers, a special key lever, a group `of code perforating punches, means under the Acontrolof any one of said set of principal key levers for conditioning said punches permutably, means ,for advancing a tape one step distance following each actuation of `one, of said principal key levels, and means for retracting said tape a distance corresponding to a plurality of steps in response to the actuation of said special key lever.

17. In a keyboard control perforating apparatus, a sprocket wheel carrying shaft for moving a perforated tape during process of preparation, pavvl and ratchet actuating mechanism for rotating said sprocket .wheel and said shaft in one direction, and a gear train forrotating said shaft in the opposite direction for retracting said perforated tape.

18. In a key lever controlled tape preparing machinea sprocket having meshing engagement with a tape under process of code preparation, means for operating said sprocket intermittently, means for operating said sprocket continuously during limited time intervals, and a common power source selectively coupled to either of said operating means under the control of certain key levers of said machine to propell said tape in either direction corresponding to the coupling of said power swords.

` 19. In a key lever operated machine, an intermittent motion apparatus, a power source for motivating said apparatus, coupling means for connecting said power source and said apparatus, a key lever for initiating said coupling means, a tolling device for measuring the number of operations of said apparatus, and a declutching means for uncoupling said power source and said apparatus under control oflsaid tolling device.

20. In akeyboard control device, a manipulator, a response device, power means for operating said responsedevice once for each actuation of said ,manipulaton a second manipulator, andmeans for latching said power means and said response device to effect aplurality of operations of saidresponse device under the control of said second manipulator.

2,1.l Ina keyboard control device, a first key, a

`second key.. aresponse device, a :power source` responsive to the actuation of either of said keys for initiating said response device, a latch for holding said second key in actuating condition upon its being depressed, and a tolling apparatus responsive to a certain number of operations of said response device to release said second key.

22. In a tape transmitter, a tape feed shaft, a tape senser, a driven means for operating both said shaft and said senser, a driving means for said driven means, a controller responsive to a slack condition in the tape for coupling said driving and driven means together, and a manipulator for coupling said driving means to said tape feed shaft alone for effecting the feeding out of tape during a dormant condition of said senser.

23. The combination set forth in claim 22 including an operation tolling device responsive to a predetermined number of tape feed shaft operations under control of said driven means for releasing said manipulator and for thereby uncoupling said driving means from said tape feed shaft.

24. In a tape transmitter, a tape feed shaft, a set of tape sensing levers, a driven shaft having cam means thereon for actuating said tape feed shaft in tape advancing direction and said tape sensing levers, a gear train for rotating said tape feed shaft in tape retracting direction, a control lever for coupling said gear train to said tape feed shaft, latching means for holding said control lever in gear coupling condition, a bar under the supervision of said control lever for holding said tape sensing levers in retracted position, a tape slack responsive device for coupling said cam means to a driving source, and a tolling mechanism for counting the number of operations of said cam means and for thereafter releasing said latching means.

25. In a combined keyboard perforator and tape transmitter unit, a perforator tape feed shaft, a transmitter unit tape feed shaft, means responsive to a predetermined tape surplus between said shafts for releasing for rotation said transmitter tape feed shaft, a manuallly operable lever for initiating a plurality of operations of said perforator tape feed shaft, and a manipulation means for coupling a reverse direction driving source to both said transmitter and perforator tape feed shafts to move a tape in a reverse direction through said tape transmitter unit and keyboard perforator.

26. In combination, a keyboard perforator comprising a set of key levers manually depressible for making code combinations of perforations in a tape, a tape transmitter responsive to the perforations in the tape for issuing corresponding permutation code line signals, a supporting structure for holding said perforator and transmitter in spaced relation one to the other, a probing means for determining the amount of prepared tape accumulation between said transmitter and perforator, a transmitter initiating lever under the supervision of said probing means, a manual release for advancing the tape a distance commensurate with the space intervening said perforator and transmitter, a retracting device responsive to manual initiation for moving the tape in a retractile direction in both said transmitter and perforator devices, and a distributor arresting means conditioned by the operation of said retracting device for preventing the operation of said distributor during the subsequent effectiveness of said probing member.

27. In a keyboard controlled device, a manipulation key, a mechanism responsive to the operation of said key, means to latch said key in operated position following its manual operation, apparatus for tolling off a predetermined number of operations of said response mechanism, and means to render said latching means ineffective after said predetermined number of operations has been tolled off.

28. In a keyboard mechanism, a plurality of key levers, a set of code elements, means to operate said code elements in combinations according to the depression of any one of said key levers, means to make code markings in a record receiving material according to said code elements operated, a special key lever, means responsive to the operation of said special key lever to advance said record receiving material, and latching apparatus controlled by said special key lever for holding all of said code elements in the same position while said record receiving material is advanced thereby.

29. In a control form preparing machine, means to advance a web step by step, a set of key levers each effective to operate said form advancing means, a special key lever for retracting said fform, and means controlled by said special key lever to disable said set of key levers during the time that said form is being retracted.

30. In a control form preparing machine, a special response mechanism, a tape advancing mechanism comprising a sprocket wheel having teeth for engaging perforations in a tape, a set of manipulators, means responsive to the actuation of any said manipulators for initiating said individual response mechanism and for concurrently actuating said tape advancing device to move said tape in a forward direction, a special key lever, and means responsive to the actuation of said special key lever for disabling said special response mechanism and for concurrently moving said tape in a reverse direction.

31. In combination, a tape perforator, a tape transmitter, key actuated means for controlling the operation of said tape perforator, means under the control of the record material between said perforator and transmitter for controlling the operation of said transmitter, means for feeding out a predetermined amount of tape for insuring that the last character perforated is transmitted, means for backfeeding said predetermined amount of tape to enable the perforation of a continuous record, and means for bringing said last perforated record to the transmitting position before transmission.

32. In a tape propelling apparatus, a shaft having a sprocket wheel for engaging perforations in a tape, a ratchet Wheel, and a gear wheel, a pawl for imparting step-by-step rotation to said shaft by intermittent actuation of said ratchet Wheel, a driving gear for imparting continuous rotation to said shaft by engagement with said gear wheel, a source of operating power, and means for coupling said source of power selectively to either said pawl or said driving gear for accordingly moving said tape in a step-by-step manner or in a continuous manner.

33. In a keyboard telegraph apparatus, a shaft having a sprocket wheel with peripheral teeth for engaging feed holes in a tape, a ratchet wheel integrally associated with said shaft, a pawl normally out of engagement With said ratchet wheel, mechanism responsive to a certain keyboard operation for bringing said pawl into engagement with and rotating said ratchet wheel and said shaft a single step distance .to correspondingly feed said tape, a gear Wheel integrally associated with said shaft, and a driving gear responsive to a certain other keyboard operation for imparting rotation to said gear Wheel and said shaft continuously to feed said tape correspondingly.

34. In a control form machine, mechanism for advancing a form intermittently during preparation a unit distance for each signal making operation of said machine, means for feeding said form continuously, and a manipulator device including means for initiating said form feeding means to cause a form to be moved a distance corresponding to a predetermined plurality of said unit distances in response to a single manipulation.

35. In a keyboard apparatus, a shaft driven from a continuous source of power, a set of key levers each operative to couple said driven shaft to a function element during a single cycle of operation of said shaft, a special key lever to couple a function element to said shaft, means for latching said special key lever in operative position, and a release mechanism responsive to a predetermined number of cycles of operation of said shaft to release said latching means and thereby to uncouple said shaft from said function element.

36. In a keyboard control unit, a set of principal key levers, a special key lever, a form feeding mechanism actuated by each of said principal and special key levers comprising a pawl and ratchet feed for advancing the form one step coincident with each pawl actuation, a latch for holding said special key lever in depressed position following its manipulation, and a feed apparatus tolling device responsive to a predetermined number of pawl feeding operations for releasing said latch to permit said special key lever to return to nondepressed position.

LOUIS M. POTTS. 

